It combines PyImport_ImportModule() and PyObject_GetAttrString()
and saves 4-6 lines of code on every use.
Add also _PyImport_GetModuleAttr() which takes Python strings as arguments.
It was initially added to support atomic groups, but that
support was never fully implemented, and CALL was only left
in the compiler, but not interpreter and parser.
ATOMIC_GROUP is now used to support atomic groups.
Limit the maximum capturing group to 2**30-1 on 64-bit platforms
(it was 2**31-1). No change on 32-bit platforms (2**28-1).
It allows to reduce the size of SRE(match_context):
- On 32 bit platform: 36 bytes, no change. (msvc2022)
- On 64 bit platform: 72 bytes -> 56 bytes. (msvc2022/gcc9.4)
which leads to increasing the depth of backtracking.
* Move the code for generating Modules/_sre/sre_constants.h from
Lib/re/_constants.py into a separate script
Tools/scripts/generate_sre_constants.py.
* Add target `regen-sre` in the makefile.
* Make target `regen-all` depending on `regen-sre`.
